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KenG

H-Beta filters

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I had a bash last year with an H-Beta on M42 and found the results quite pleasing if i'm honest. 

The nebula wasn't exact;y well placed at the time being low down in the western sky. i seem to remember using my 20mm eyepiece. It really brought the 'bats wing' areas of the nebula out very nicely and gave what i thought was a very satisfying view. I was hoping to have another go at it last weekend from a dark sky site in Wales but unfortunately it clouded over before Orion had appeared. 

I intend on getting one of these filters myself (when finances permit) as I would also like to try some other targets not normally associated with its use.

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Steve, If you want to borrow mine for a bash at the HH when you go back to Wales, you are more than welcome mate.

Mine is an Orion, showed us the HH in both my 14" and a 16" LB.

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I just noted I missed this thread - and I am a certified Filter-Nut! I have more filters than I can remember - and love 'em all. I have a H-b from Astronomik. It rarely gets used as it's rather limited in which objects it works well on, but I enjoy experimenting. However my purpose in this thread is to pass on some light, so here's a link:

http://www.prairieastronomyclub.org/?s=Filter

You will find some excellent, well-researched articles on filters and DSO relationships there.

Enjoy!

Dave

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I've recently bought a 20mm TV plossl for the same reason. With my 12" dob it gives a 3.8 mm exit pupil which I believe is in the right range for effective use of the H-Beta filter under my typical skies and the very high measured light transmission figures of the eyepieces was an attraction too. I did consider the 25mm but I felt that the additional magnification (= darker background sky) and smaller true field of the 20mm with my scope might help tip the balance a little further in my favour.

I have also washed my primary and secondary mirrors, part flocked the scope and blackened the secondary edge since I last tried for these faint objects so, short of buying a larger aperture scope, I'm as ready as I can be I think.

We will see ! :smiley:

That is good, I have been considering giving my Primary mirror a wash and have purchased a kids paddling pool to facilitate this. I can then complete the flocking at the same time.

Whilst the O-III filter is the key to revealing the veil, the H-beta is perhaps the key for the Horse Head, though there the similarity ends. The Veil of course is dramatic and spectacular, the Horse Head I expect to be underwhelming visually, yet encountering it, emotively speaking, will be a complete high. 

My own best chance will I think be to head into a site I have in mind in deepest Northumberland to weedle out the darkest sky possible. This will involve an overnight probably wild camp trip, as it will exceed my usual 50 min or so journeys. However look forward to attempting this target at different locations when conditions and circumstances permit.

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Actually just to add, I had considered the 20mm plossl to, though the 25mm with an exit pupil of just over 5mm in my scope, will I expect be applicable to dark sky conditions.

Edited by scarp15
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Guys,

We're definitely taking about bandwidths in nm not A.

For what it's worth, the normal Hbeta emission is 50% that of the Ha emission...extra dusty environment may change the ratio slightly.

This infers that you would record twice as much light in the same object just with an Ha filter.....

Night vision (governed by the spectral response of the rods) has about zero sensitivity in H-alpha:

em-spectrum_human-eye_asu_380x300.gif

H-alpha would only work if the object is bright enough to trigger the cones. The HH is no such object. I have found the HH with my C8, and it did look like a small hole or dark gap in the line defining the boundary of the emission nebula, rather than having a clearly defined shape (at 65.5x). I used a fairly cheap H-beta filter. I spotted the California with UHC, I will try H-Beta next time round.

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Night vision (governed by the spectral response of the rods) has about zero sensitivity in H-alpha:

em-spectrum_human-eye_asu_380x300.gif

H-alpha would only work if the object is bright enough to trigger the cones. The HH is no such object. I have found the HH with my C8, and it did look like a small hole or dark gap in the line defining the boundary of the emission nebula, rather than having a clearly defined shape (at 65.5x). I used a fairly cheap H-beta filter. I spotted the California with UHC, I will try H-Beta next time round.

Michael your view of the California Neb with the UHC - was it with your 8" SCT or one of your 80mm fracs? I assume it was from a dark site with Perseus being high up. I have tried so many times with various scopes but never succeeded despite knowing exactly where it is.

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I spotted this with my C8 from my back garden on a very transparent night, with Perseus at zenith. With the 31T5 "Panzerfaust" I noticed that the sky background in one elongated patch of sky was brighter than the immediate surroundings. Must try with the APM 80mm one day.

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I spotted this with my C8 from my back garden on a very transparent night, with Perseus at zenith. With the 31T5 "Panzerfaust" I noticed that the sky background in one elongated patch of sky was brighter than the immediate surroundings. Must try with the APM 80mm one day.

Be sure to share your results if you get around to this, Michael!  I for one would be keenly interested!

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Be sure to share your results if you get around to this, Michael!  I for one would be keenly interested!

Me too, but the skies must cooperate, alas

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Just checking the price of the 2" Hydrogen Beta filters, and I can see prices ranging from £33 - £146. Is there that much difference in the quality of these filters? The filter seems to have limited use, so I might be tempted on the bargain priced one and see if it works.

Dave

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7 hours ago, Astralstroll said:

Just checking the price of the 2" Hydrogen Beta filters, and I can see prices ranging from £33 - £146. Is there that much difference in the quality of these filters? The filter seems to have limited use, so I might be tempted on the bargain priced one and see if it works.

Dave

I think most of the experienced guys are using the Astronomik version. I believe there’s one of these for sale in the classifieds on here for about £100. I feel sure @Mark at Beaufort was using one of the Sky’s the Limit ones with good results which is more towards the lower budget end. I personally went for the Astronomik on the grounds that targets you’d use the H-Beta filter on tend to be the fainter and more challenging ones. As such, I wanted the best quality filter I could afford. I’ve only give it one quick test run so far so it’s too early to say if that was the right decision!

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7 hours ago, Astralstroll said:

Just checking the price of the 2" Hydrogen Beta filters, and I can see prices ranging from £33 - £146. Is there that much difference in the quality of these filters? The filter seems to have limited use, so I might be tempted on the bargain priced one and see if it works.

Dave

Check the band pass data before committing. I bought a low cost H-Beta filter a couple of years ago and found that the maximum H-Beta line pass was just 75%. No good for visual - you need 90% or more really.

Currently I have an Astronomik 1.25" H-Beta because the eyepieces that I use it with (occasionally - it does not get much use) are that fitting. I did manage to see the Horsehead Nebula (just about !) with this H-Beta filter so it's done a good job for me :smiley:

 

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Neil is correct that I purchased a Sky's the Limit H.Beta filter. However, it was more involved in  that. Alan the owner checked a large number of filters to give me the bandwidth that I required - yes there was a lot of difference between them. I need to find the graph but the transmission was over 90%. I have used this filter in my 15x70 Helios Apollo Binos and with another H.Beta filter on the other eyepiece gave me a nice view of the California Nebula. 

 

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